A1 2011 Front brake caliper Banjo Bolt size

[Pigsfoot]

Hi, I have just replaced the front brake calipers on my A1 and the banjo bolts are worn and i just cant get them tight enough to seal ( I have replace the copper washers ) as they are very slightly weeping. 11mm spanner is to loose, 10mm to small and nothing imperial fits either 😤

For the life of me i cant find spares on the web, lots for A3's and various ones listed by size.

Can anyone provide me either either a part number or the dimensions so i can get a new pair ordered